Portable vacuum or blower/vacuum unit

ABSTRACT

A portable vacuum or blower/vacuum unit ( 10 ) having a motor ( 11 ), a fan ( 12 ), at least one air conduit ( 15 ) with a first portion ( 16 ) to receive the air flow generated by the fan and a second portion ( 17 ) remote from the fan ( 12 ), a mesh screen ( 18 ) within the air conduit ( 15 ) closely adjacent to the fan ( 12 ) to protect the fan ( 12 ) from the flow of debris along the air conduit, ( 15 ) and a stirrer ( 21 ) for deflecting debris away from the mesh screen ( 18 ), wherein the fan ( 12 ) is located to one side of the first portion ( 16 ) of the air conduit ( 15 ); and the second portion ( 17 ) of the air conduit ( 15 ) is able to be located in a position where the angle alpha between a longitudinal axis of the second portion ( 17 ) of the air conduit ( 15 ) and a radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the (fan  12 )) is obtuse, so as to permit sufficient air conduit to at least substantially bypass, or to otherwise be deflected from the mesh screen ( 18 ).

FIELD OF THE INVENTION

This invention relates to portable vacuum units or portable blower/vacuum units.

BACKGROUND OF THE INVENTION

In conventional portable vacuum units or blower/vacuum units, the dust or debris collected is sucked along the cleaning pipe and ultimately passes through the fan which is located at a right angle to the direction of the air flow pipe. FIG. 1 shows an example of a conventional vacuum unit or blower/vacuum unit. The unit has a fan 1 which is rotationally driven by a motor. Dust or debris is sucked by the fan 1 from the end of a cleaning pipe 2 through a suction opening 3 of the fan 1, and discharged from a discharge outlet 4 into a dust collector (in this case, a bag of an air permeable fabric) 5. The dust is collected in the collector and air is released into the atmosphere through the fabric of the collector. The dust or debris is sucked by the fan from the end of the cleaning pipe 2 through the fan 1 and into the dust collector 5.

The above arrangement may be very effective in collecting dust and other small particles but has the clear disadvantage that, in use, debris is likely to catch on the blades of the fan or become caught in the fan housing reducing efficiency or damaging the fan or the fan housing. Further, the fan is likely to be damaged by certain debris of larger size, particularly bottles or cans, and which may be unable to pass through the fan. This may also put pressure on the fan housing causing it to crack or break.

One way of overcoming this problem has been the use of a mesh screen. In a further embodiment of a vacuum unit or blower/vacuum unit shown in FIG. 2, dust or debris sucked from the end of the cleaning pipe 2 is collected by a mesh screen 6. Air is then sucked through suction opening 3 of the fan 1, passes through the fan 1 and is released into the atmosphere through a discharge outlet 4. While this arrangement may prevent larger debris from passing through the fan, the mesh screen may become clogged with debris of larger size. This may also put pressure on the fan housing causing it to crack or break.

An alternative way of overcoming this problem has been by the use of a confluence pipe. FIG. 3 shows a known dust collector in which a fan 1 has a discharge outlet 4 which communicates with an air pipe 7. The fan 1 which is rotationally driven by a motor produces an air blast. The air blast from the fan 1 flows through the air pipe 7 and confluence pipe 8 into the collector 5. In the confluence pipe 8, this air blast draws air from the cleaning pipe 2 into the collector 5. Although this arrangement avoids clogging of debris near the fan, this makes it more difficult to produce a sufficient or the same level of suction. While adjustments can be made to the motor and fan to increase the suction force, this is less efficient and tends to result in a heavier and/or more cumbersome unit.

Any reference to prior art in this specification does not constitute and should not be taken as an acknowledgement that this prior art forms part of the common general knowledge in Australia or any other country.

SUMMARY OF THE INVENTION

The present invention is directed to a portable vacuum unit, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice.

In one form the invention resides in a portable vacuum unit having:

a motor;

a fan;

at least one air conduit with a first portion to receive the air flow generated by the fan and a second portion remote from the fan;

at least one mesh screen within the air conduit closely adjacent to the fan to protect the fan from the flow of debris along the air conduit;

a stirrer for deflecting debris away from the at least one mesh screen,

wherein the fan is located to one side of the first portion of the air conduit; and

the second portion of the air conduit is able to be located in a position where an angle α between the longitudinal axis of the second portion of the air conduit and the radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the fan) is obtuse, so as to permit sufficient air flow along the air conduit but which allows the suction of debris along the air conduit to at least substantially bypass, or to otherwise be deflected from the mesh screen. FIG. 4 is a schematic diagram showing the angle α between the longitudinal axis of the second portion of the air conduit and the line between x1 and x2 in the radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the fan).

Preferably, the angle α (as defined below in FIG. 4) between the longitudinal axis of the second portion of the air conduit and the line between x1 and x2 (shown below in FIG. 4) in the radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the fan) is obtuse.

Wherever any reference to the angle α appears in this specification and claims, this angle is that defined in FIG. 4.

In a preferred embodiment of the invention, the angle α is in the range 155° to 165° inclusive.

In a further preferred embodiment, the angle α is 160°.

The air conduit may be one integrally formed piece. However, in a preferred embodiment of the invention the first and second portions of the air conduit are separate pieces.

Preferably, the first and second portions of the air conduit are comprised of one or more pipes or tubes.

In a further alternative preferred embodiment of the invention, the second portion of the air conduit may be selectively connected with either a suction circuit so as to operate as a vacuum unit or alternatively to a discharge circuit communicating with the discharge outlet of the first portion of the air conduit so as to operate as an air blower. This blower/vacuum unit can therefore selectively be used to either suck debris or blow and gather debris. The blower/vacuum unit may be interchangeable between vacuum and blower functions by, for example, moving the arrangement of the second portion between the suction and discharge circuit. The blower/vacuum unit may be converted from vacuum mode to blower mode, by disconnecting the second portion of the air conduit from the first portion and by connecting the second portion to the discharge outlet of the first portion. The second portion may be connected to the first portion and the discharge circuit by any suitable means such as by a screw in or a snap fit arrangement.

Alternatively, in a further preferred embodiment of the invention the interchange between vacuum and blower functions may be achieved by other means such as by utilising a valve between the suction circuit and the discharge circuit.

In a further preferred embodiment, the stirrer may have one or more raised flanges, preferably one at each end, to deflect debris from the at least one mesh screen. According to a first embodiment, the stirrer may extend across approximately half the diameter of the fan. The stirrer according to this embodiment will have a centre of rotation with is coaxial with the centre of rotation for the fan.

In a second embodiment, the stirrer may extend across substantially the diameter of the fan. The stirrer according to this embodiment also has a centre of rotation with is coaxial with the centre of rotation for the fan. One or more raised flanges may be provided on the stirrer and each raised flange is preferably located approximately midway between an outer end of the stirrer and the centre of rotation. The stirrer may be annodated or S-shaped in configuration.

The mesh screen may be constructed of metal wire or any other suitable material including a plastics material such as polyurethane. The mesh screen will typically be provided as a planar sheet member and it may be of the same cross-sectional shape as the fan or fan housing. The mesh screen may be an annular mesh screen.

According to a particularly preferred embodiment of the present invention, there may be at least two and generally a pair of mesh screens provided. Each of the mesh screens will typically be planar members and generally of circular shape.

The first mesh screen will typically be mounted adjacent the fan. This first mesh member will typically be annular in shape. It will also typically have openings therein to prevent particular sized material from passing through the screen.

The second mesh screen will typically be mounted outwardly from the first mesh screen away from the fan. The second mesh screen may assist with the positioning an retention of the first screen. Preferably, the second mesh screen may be provided with a plurality of openings therein which are larger than the openings provided in the first mesh screen, such that the second mesh screen may perform a bulk debris removal function while the first mesh screen acts to remove finer or smaller but still potentially damaging debris from the flow.

In a further preferred embodiment, the mesh screen may be provided with an opening (which may be selectively closeable). This opening allows paper or leaf matter debris to pass through the fan so as to enable the debris to be at least partially shredded by the blades of the fan where this is desired. In one embodiment, the opening in the mesh screen is in the form of a slot. The size of the slot in the mesh screen may vary depending upon the nature of the debris to be collected.

In a further preferred embodiment, the second portion may also be tapered at its free end to form a nozzle so as to concentrate air flow. Alternatively, the nozzle may be a separate portion, or may be integrally formed with an extension pipe or tube referred to below).

In a further preferred embodiment, the blower/vacuum unit may be provided with connection means for removably or permanently securing additional parts, fittings and accessories to the unit. Such parts, fittings and accessories may include a removable debris collector for collecting dust or debris. This debris collector may take the form of a bag or any other container of suitable air permeable material and of sufficient strength to hold the intended debris. The debris collector may be connected by any suitable fastening arrangement. Other fittings may include an extension pipe or tube for extending the length of the second portion, where required.

In addition to the above, in a further preferred embodiment the vacuum or blower/vacuum unit is hand-held and may have one or more handles to assist the user in holding and manouvering the unit. The unit may optionally be provided with a shoulder strap, also to assist the user in holding and operating the unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a first conventional vacuum or blower/vacuum unit.

FIG. 2 is a schematic illustration of a second conventional vacuum or blower/vacuum unit.

FIG. 3 is a schematic illustration of a third conventional vacuum or blower/vacuum unit.

A preferred form of the present invention will now be described, by way of example, with reference to the accompanying drawings wherein:

FIG. 4 is a schematic diagram showing the angle α between the longitudinal axis of the second portion of the air conduit and the line between x1 and x2 in the radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the fan).

FIG. 5 is a perspective view of the unit according to an embodiment of the invention showing the unit in vacuum mode.

FIG. 6 is a side view of the unit according to an embodiment of the invention in FIG. 5 showing the reverse internal side of the unit.

FIG. 7 is a top view of the fan, stirrer and associated components shown in FIG. 5 disassembled.

FIG. 8 is a further view of the unit of FIG. 5 from the air discharge outlet (without a collector attached).

FIG. 9 is a side view of the unit according to an alternative embodiment of the invention showing where the unit is able to be converted between vacuum mode and blower mode.

FIG. 10 is a top view of a second embodiment of the fan, stirrer and associated components.

FIG. 11 is a side view of the fan, stirrer and associated components as illustrated in FIG. 10.

FIG. 12 is a perspective view of the fan, stirrer and associated components as illustrated in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring generally to the accompanying drawings, there is depicted a vacuum unit 10. The vacuum unit 10 has a motor 11 and a fan 12 which is rotationally driven by the motor 11: The fan has a central hub 13 and impeller blades 14. The vacuum unit 10 has an air conduit in the form of air pipe 15 with a first portion 16 and second portion 17, the first portion 16 being nearest the fan and the second portion 17 being remote from the fan. The fan 12 is located to one side of the first portion 16 of the air pipe 15 and is protected on the side which communicates with the air pipe by a mesh screen 18. The mesh screen 18 is located within the air pipe 15 closely adjacent to the fan 12 to protect the fan from the flow of debris along the air pipe 15. The fan 12 also has a fan housing 19 which is typically moulded from a structural plastic material to protect the fan 12 against interference and to protect the user from the fan.

The fan impeller defines a radial plane which is perpendicular to the axis of rotation of the fan 12. The second portion 17 of the air pipe 15 is able to be located in a position where the angle α between the longitudinal axis of the second portion of the air pipe 15 and a line in the above radial plane (which is perpendicular to the axis of rotation of the fan 12) is obtuse, so as to permit sufficient air flow along the air pipe 15 but which, in vacuum mode, allows the suction of debris along the air pipe 15 to at least substantially bypass, or to otherwise be deflected from the mesh screen 18. The above angle is shown schematically in FIG. 4.

In use, the free end of the second portion 17 is pointed towards dust or other debris. Debris is sucked into the second portion 17, passes along the air pipe 15 and discharged through discharge outlet 20.

A stirrer 21 is affixed to a bolt 22 located through the central hub of the fan 12 and secured in place by washer 23 so that the stirrer 21 rotates with the rotation of the fan 12. The stirrer 21 has a raised flange 24A and 24B at each end. The stirrer 21 assists in deflecting debris away from the mesh screen 18 and consequently also away from the fan 12. The stirrer 21 according to this embodiment, extends across approximately half the diameter of the fan 12 and has a centre of rotation with is coaxial with the centre of rotation for the fan 12.

Although the air pipe 15 is shown in one piece, the first portion 16 and second portion 17 may either be one integrally formed piece or may be separate pieces. The second portion 17 may be selectively connected with either a suction circuit so as to operate as a vacuum unit or alternatively to a discharge circuit communicating with the discharge outlet 20 so as to operate as an air blower. The blower/vacuum unit 10 can therefore be used selectively to either suck debris or blow and gather debris. The blower/vacuum unit 10 may be interchangeable between vacuum and blower functions by, for example, moving the arrangement of the second portion 17 between the suction and discharge circuit. The unit may be converted from vacuum mode to blower mode, by disconnecting the second portion 17 from the first portion 16 at or in the vicinity of the notional line marked 25A to 25B and by connecting the second portion 17 to the discharge outlet 20 of the first portion 16 (as shown in the schematic diagram in FIG. 9). The second portion may be connected to the first portion and the discharge circuit by any suitable means such as by a screw in or a snap fit arrangement.

Alternatively, the interchange between vacuum and blower functions may be achieved by other means such as by utilising a valve between the suction circuit and the discharge circuit.

Although not shown, the mesh screen 18 may also be provided with an opening such as a slot (which may be selectively closeable).

Although not shown, the second portion 17 may be tapered at its free end to form a nozzle to concentrate the air flow.

Although not shown, the vacuum or blower/vacuum unit 10 may be provided with connection means for removably or permanently fitting additional parts, fittings and accessories to the unit. Such parts, fittings and accessories may include a removable debris collector for use in vacuum mode to collect dust or debris. This debris collector is attached at discharge outlet 20. The debris collector may take the form of a bag or any other container of suitable air permeable material and of sufficient strength to hold the intended debris. The debris collector may be connected by any suitable fastening arrangement. Other fittings may include an extension pipe or tube for extending the length of the second portion, where required.

The vacuum or blower/vacuum unit 10 may have one or more handles 26 and may also optionally be provided with a shoulder strap (not shown).

A second preferred embodiment of the fan, stirrer and associated components is illustrated in FIGS. 10 to 12. In the second embodiment, the stirrer 21 extends across substantially the diameter of the fan 12. A pair of raised flanges 24A, 24B are provided on the stirrer 21 and each flange is located approximately midway between an outer end of the stirrer 21 and the central hub 13.

According to this embodiment of the present invention, there is a pair of mesh screens provided, each of which are planar members and circular shape.

The first mesh screen SO is mounted adjacent the fan. This first mesh screen 50 is annular in shape and has a plurality of openings therein to prevent particular sized material from passing through the screen.

The second mesh screen 51 is mounted outwardly from the first mesh screen 50 away from the fan 12. The second mesh screen 51 assists with the positioning and retention of the first mesh screen 50. The second mesh screen 51 is provided with a plurality of openings therein which are larger than the openings provided in the first mesh screen 50, such that the second mesh screen 51 performs a bulk debris removal function while the first mesh screen 50 acts to remove finer or smaller but still potentially damaging debris from the flow.

In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers. 

1. A portable vacuum unit having: a motor; a fan; at least one air conduit with a first portion to receive the air flow generated by the fan and a second portion remote from the fan; a mesh screen within the air conduit closely adjacent to the fan to protect the fan from the flow of debris along the air conduit; a stirrer for deflecting debris away from the mesh screen; wherein the fan is located to one side of the first portion of the air conduit; and the second portion of the air conduit is able to be located in a position where the angle α between a longitudinal axis of the second portion of the air conduit and a radial plane defined by the fan impeller (which is perpendicular to the axis of rotation of the fan) is obtuse, so as to permit sufficient air flow along the air conduit but which allows the suction of debris along the air conduit to at least substantially bypass, or to otherwise be deflected from the mesh screen.
 2. A portable vacuum unit according to claim 1, wherein the angle α is in the range 155° to 165° (inclusive).
 3. A portable vacuum unit according to claim 1, wherein the angle α is 160°.
 4. A portable vacuum unit according to claim 1, wherein the first and second portions of the air conduit are separate pieces, and the second portion of the air conduit may be selectively connected with either a suction circuit so as to operate as a vacuum unit or alternatively to a discharge circuit communicating with the discharge outlet of the first portion of the air conduit so as to operate as an air blower.
 5. A portable vacuum unit according to claim 1, wherein the unit may be converted from vacuum mode to blower mode, by disconnecting the second portion of the air conduit from the first portion and by connecting the second portion to the discharge outlet of the first portion.
 6. A portable vacuum unit according to claim 1 wherein the stirrer has one or more raised flanges to assist in deflecting debris from the mesh screen.
 7. A portable vacuum unit according to claim 6 wherein the stirrer has a raised flange at each end to deflect debris from the mesh screen.
 8. A portable vacuum unit according to claim 1 wherein the mesh screen is provided with an opening.
 9. A portable vacuum unit according to claim 8 wherein the opening in the mesh screen is in the form of a slot.
 10. A portable vacuum unit according to claim 1 wherein the second portion includes a cleaning pipe attachable relative to the first portion, the cleaning pipe having a tapered nozzle at a free end to concentrate air flow.
 11. A portable vacuum unit according to claim 1 wherein the blower/vacuum unit may be provided with connection means for removably or permanently securing additional parts, fittings and accessories to the unit.
 12. A portable vacuum unit according to claim 1 further including a removable debris collector for collecting dust or debris.
 13. A portable vacuum unit according to claim 1 wherein the vacuum unit is hand-held and may have one or more handles.
 14. A portable vacuum unit according to claim 1 wherein the vacuum unit is provided with a shoulder strap.
 15. A portable vacuum unit according to claim 10 wherein the vacuum unit has an extension pipe or tube for extending the length of the cleaning pipe. 